This dissertation attempts to fully explain the aerodynamic ground effect phenomenon, which occurs when a wing flies over a nearby plane. The long-term motivation is to determine the feasibility of a train that achieves aerodynamic levitation above a flat guideway. Such a train would rely exclusively on lifting surfaces, rather than on steel wheels, lifting fans, or magnetic fields.;As a first step in the study of an aerodynamically suspended train, a wing section must be designed. This dissertation focuses on the preliminary design and the experimental investigation of a two-dimensional airfoil in ground effect. For application to high-speed ground transportation, the airfoil is assumed to fly at approximately six degrees incidence and a ground distance of ten percent of its chordlength. Both the theoretical analysis and the wind tunnel experiment utilize two airfoils that are mirror images of one another. The symmetry plane between the two airfoils models the presence of the ground. The theoretical preliminary design makes use of inviscid panel methods.;The work includes chapters on vehicles that use the aerodynamic ground effect, and on high-speed ground transportation systems. Possible directions for future research in the area of aerodynamically suspended trains are also suggested.